Abstract
Abstract: :
Purpose: We propose that neurosensory retina does not function over a bed where choroidal neovascularization (CNV) has been removed and that neurosensory retina moved off a CNV site has comparatively better function. We compare retinal function in three areas after macular translocation surgery to evaluate the separate contribution of the RPE choroidal bed versus existing neurosensory retinal damage to poor visual function after surgery for age–related macular degeneration. Design: Cross–sectional study within a prospective, clinical case series. Methods: We studied retinal sensitivity across three areas of visual field in 44 patients who had macular translocation with 360 degree peripheral retinectomy for large subfoveal CNV due to age–related macular degeneration. Using Nidek MP1 data, the median sensitivity score (MSS) for the central 10–degrees (Area 1) was compared to two areas symmetric in distance from the fovea. Flourescein angiograms were reviewed for location and extent of the postoperative RPE disturbance at the site of CNV removal. Area 1 was abnormal retina over healthy RPE bed (central 10 degrees over macula); Area 2 was normal retina over an RPE bed damaged by CNV removal; and Area 3, the control area, was normal retina over healthy RPE bed. Results: The MSS for Area 1 was 3.8 ± 5.0 (range –2.0 to 14.0), Area 2 was –1.7 ± 1.6 (range –2.0 to 8.0), and Area 3 was 8.0 ± 4.4 (range –2.0 to 14.0). Area 1 was a median of 5.5 decibels greater in sensitivity (range 16 greater to 2 poorer) than Area 2 (p ≤ 0.001) and 4.2 decibels poorer in sensitivity (range 3 greater to 10 poorer) than Area 3 (p ≤ 0.001). Conclusions: Retinal sensitivity over Area 1 was much better than that in Area 2, even though Area 2 began with healthy neurosensory retina placed over abnormal choriocapillaris RPE bed. This supports our hypothesis that areas without healthy RPE would have the poorest sensitivity. Foveal sensitivity is diminished even after macular translocation, when compared to an eccentric area of retina unaffected by AMD (Area 3).
Keywords: visual fields • age-related macular degeneration • choroid: neovascularization